From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: MSI interrupts and disable_irq Date: Sat, 06 Oct 2007 13:59:13 -0400 Message-ID: <4707CCF1.8080909@pobox.com> References: <46FC15A9.1070803@nvidia.com> <46FDBCB4.9090802@pobox.com> <86802c440710061043u6e51cd7q468346bd06b08657@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Ayaz Abdulla , Manfred Spraul , nedev , Linux Kernel Mailing List , David Miller , Andrew Morton To: Yinghai Lu Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:55811 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756750AbXJFR7b (ORCPT ); Sat, 6 Oct 2007 13:59:31 -0400 In-Reply-To: <86802c440710061043u6e51cd7q468346bd06b08657@mail.gmail.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Yinghai Lu wrote: > On 9/28/07, Jeff Garzik wrote: >> Ayaz Abdulla wrote: >>> I am trying to track down a forcedeth driver issue described by bug 9047 >>> in bugzilla (2.6.23-rc7-git1 forcedeth w/ MCP55 oops under heavy load). >>> I added a patch to synchronize the timer handlers so that one handler >>> doesn't accidently enable the IRQ while another timer handler is running >>> (see attachment 'Add timer lock' in bug report) and for other processing >>> protection. >>> >>> However, the system still had an Oops. So I added a lock around the >>> nv_rx_process_optimized() and the Oops has not happened (see attachment >>> 'New patch for locking' in bug report). This would imply a >>> synchronization issue. However, the only callers of that function are >>> the IRQ handler and the timer handlers (in non-NAPI case). The timer >>> handlers use disable_irq so that the IRQ handler does not contend with >>> them. It looks as if disable_irq is not working properly. >>> >>> This issue repros only with MSI interrupt and not legacy INTx >>> interrupts. Any ideas? >> (added linux-kernel to CC, since I think it's more of a general kernel >> issue) >> > I wonder if the race is between soft_timer for nv_do_nic_poll from > different CPUs Interested parties should try the forcedeth patches I just posted :) Jeff